<s>
In	O
computing	O
,	O
remote	B-General_Concept
direct	I-General_Concept
memory	I-General_Concept
access	I-General_Concept
(	O
RDMA	B-General_Concept
)	O
is	O
a	O
direct	B-General_Concept
memory	I-General_Concept
access	I-General_Concept
from	O
the	O
memory	O
of	O
one	O
computer	O
into	O
that	O
of	O
another	O
without	O
involving	O
either	O
one	O
's	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
This	O
permits	O
high-throughput	O
,	O
low-latency	O
networking	O
,	O
which	O
is	O
especially	O
useful	O
in	O
massively	O
parallel	O
computer	B-Architecture
clusters	I-Architecture
.	O
</s>
<s>
RDMA	B-General_Concept
supports	O
zero-copy	O
networking	O
by	O
enabling	O
the	O
network	B-Protocol
adapter	I-Protocol
to	O
transfer	O
data	O
from	O
the	O
wire	O
directly	O
to	O
application	O
memory	O
or	O
from	O
application	O
memory	O
directly	O
to	O
the	O
wire	O
,	O
eliminating	O
the	O
need	O
to	O
copy	O
data	O
between	O
application	O
memory	O
and	O
the	O
data	O
buffers	O
in	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Such	O
transfers	O
require	O
no	O
work	O
to	O
be	O
done	O
by	O
CPUs	B-General_Concept
,	O
caches	B-General_Concept
,	O
or	O
context	B-Operating_System
switches	I-Operating_System
,	O
and	O
transfers	O
continue	O
in	O
parallel	O
with	O
other	O
system	O
operations	O
.	O
</s>
<s>
As	O
of	O
2018	O
RDMA	B-General_Concept
had	O
achieved	O
broader	O
acceptance	O
as	O
a	O
result	O
of	O
implementation	O
enhancements	O
that	O
enable	O
good	O
performance	O
over	O
ordinary	O
networking	O
infrastructure	O
.	O
</s>
<s>
For	O
example	O
RDMA	B-Operating_System
over	I-Operating_System
Converged	I-Operating_System
Ethernet	I-Operating_System
(	O
RoCE	O
)	O
now	O
is	O
able	O
to	O
run	O
over	O
either	O
lossy	O
or	O
lossless	O
infrastructure	O
.	O
</s>
<s>
In	O
addition	O
iWARP	B-Device
enables	O
an	O
Ethernet	O
RDMA	B-General_Concept
implementation	O
at	O
the	O
physical	O
layer	O
using	O
TCP/IP	O
as	O
the	O
transport	O
,	O
combining	O
the	O
performance	O
and	O
latency	O
advantages	O
of	O
RDMA	B-General_Concept
with	O
a	O
low-cost	O
,	O
standards-based	O
solution	O
.	O
</s>
<s>
The	O
RDMA	B-General_Concept
Consortium	O
and	O
the	O
DAT	O
Collaborative	O
have	O
played	O
key	O
roles	O
in	O
the	O
development	O
of	O
RDMA	B-General_Concept
protocols	O
and	O
APIs	B-Application
for	O
consideration	O
by	O
standards	O
groups	O
such	O
as	O
the	O
Internet	O
Engineering	O
Task	O
Force	O
and	O
the	O
Interconnect	O
Software	O
Consortium	O
.	O
</s>
<s>
Hardware	O
vendors	O
have	O
started	O
working	O
on	O
higher-capacity	O
RDMA-based	O
network	B-Protocol
adapters	I-Protocol
,	O
with	O
rates	O
of	O
100Gbit/s	O
reported	O
.	O
</s>
<s>
Software	O
vendors	O
,	O
such	O
as	O
IBM	O
,	O
Red	O
Hat	O
and	O
Oracle	B-Application
Corporation	I-Application
,	O
support	O
these	O
APIs	B-Application
in	O
their	O
latest	O
products	O
,	O
and	O
engineers	O
have	O
started	O
developing	O
network	B-Protocol
adapters	I-Protocol
that	O
implement	O
RDMA	B-General_Concept
over	O
Ethernet	O
.	O
</s>
<s>
Both	O
Red	O
Hat	O
Enterprise	O
Linux	O
and	O
Red	O
Hat	O
Enterprise	O
MRG	O
have	O
support	O
for	O
RDMA	B-General_Concept
.	O
</s>
<s>
Microsoft	O
supports	O
RDMA	B-General_Concept
in	O
Windows	O
Server	O
2012	O
via	O
SMB	B-Operating_System
Direct	I-Operating_System
.	O
</s>
<s>
VMware	O
's	O
ESXi	O
product	O
also	O
supports	O
RDMA	B-General_Concept
as	O
of	O
2015	O
.	O
</s>
<s>
Common	O
RDMA	B-General_Concept
implementations	O
include	O
the	O
Virtual	B-General_Concept
Interface	I-General_Concept
Architecture	I-General_Concept
,	O
RDMA	B-Operating_System
over	I-Operating_System
Converged	I-Operating_System
Ethernet	I-Operating_System
(	O
RoCE	O
)	O
,	O
InfiniBand	B-Architecture
,	O
Omni-Path	B-Operating_System
and	O
iWARP	B-Device
.	O
</s>
